Haven't video games solved this a long time ago with age ratings on the games themselves? Sony and Microsoft's parental controls are convoluted garbage with logins galore. But Nintendo's, at least on the Switch 1, was dead simple. You enable parental controls, set an age rating, and password. Done. There's an app to set time limits, whitelist/blacklist games, etc. That was the easiest UX I've seen.

Games (apps) dont need to know the age of the user to access them. Even the parental control didn't know the child's real age. It just knew if the child had access to E, E10+, T, M, etc.

Why are we trying to reinvent this? Oh yeah more data collection.